The invention relates to a security document having a carrier substrate and at least one first film element which is fixed to the carrier substrate and shows a first optically variable effect generated by a diffractive first relief structure, wherein the security document furthermore has at least one first printing ink layer which is applied in a region-wise fashion onto the at least one first film element. The invention furthermore relates to a method for the production of such a security document.
Security documents of the abovementioned type are sufficiently known from U.S. Pat. No. 4,856,857. Here, transparent film elements which show a hologram are fixed to the substrate of a security document, for example of a deposit certificate, of a magnetic card, of a credit card and the like. The security document furthermore has a visually perceivable display region having a letter or image pattern, which shows for example personal data of the holder of the security document and is arranged directly on or in the substrate and is at least partially covered by the transparent film element. Such a letter or image pattern can also be situated on the film element or integrated in the layer structure of the film element. The principle layer structure of the film element has a transparent layer which has on one of its two sides a relief structure which generates a hologram and adjoins a thin film or a reflection layer, wherein the refractive indices of the transparent layer and of the thin film are different. The security document including the film element is coated with a transparent protective layer or is laminated between such protective layers.
It has been shown that the known security documents can be manipulated or forged by grinding off the substrate, starting from the rear side, until the film element, possibly including the protective layer, is left. Subsequently, the film element can be adhesively bonded onto another substrate, which was previously provided with the desired data. If letter or image patterns are likewise arranged on the film element or between the film element and a protective layer, they can be ground off or detached in advance starting from that side of the film element, possibly including the protective layer, which faces away from the substrate. This is followed by a new application of changed letter or image patterns onto the film element, the application of a new protective layer, the above-described grinding-off of the substrate starting from the rear side thereof, and so on.
Alternatively, a security document can be manipulated by lifting the protective layer including the film element off the substrate, inserting a thin sheet with the desired data and restoring the composite, for example by way of laminating it. If the film element on the security document is not protected by a transparent protective layer, it can be lifted off with an adhesive transparent film, the data on the substrate can be manipulated, and the film element including the transparent film, cut to the size of the film element, can be re-applied.